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erofs: avoid consecutive detection for Highmem memory 

[ Upstream commit 448b5a1548 ]

Currently, vmap()s are avoided if physical addresses are
consecutive for decompressed buffers.

I observed that is very common for 4KiB pclusters since the
numbers of decompressed pages are almost 2 or 3.

However, such detection doesn't work for Highmem pages on
32-bit machines, let's fix it now.

Reported-by: Liu Jinbao <liujinbao1@xiaomi.com>
Fixes: 7fc45dbc93 ("staging: erofs: introduce generic decompression backend")
Link: https://lore.kernel.org/r/20220708101001.21242-1-hsiangkao@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Gao Xiang 2022-07-08 18:10:01 +08:00 committed by Greg Kroah-Hartman
parent 2478e36ec4
commit 55a31d4abd
1 changed files with 10 additions and 6 deletions
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16
fs/erofs/decompressor.c
View File

@ -93,14 +93,18 @@ static int z_erofs_lz4_prepare_dstpages(struct z_erofs_lz4_decompress_ctx *ctx,
if (page) {
__clear_bit(j, bounced);
if (kaddr) {
if (kaddr + PAGE_SIZE == page_address(page))
if (!PageHighMem(page)) {
if (!i) {
kaddr = page_address(page);
continue;
}
if (kaddr &&
kaddr + PAGE_SIZE == page_address(page)) {
kaddr += PAGE_SIZE;
else
kaddr = NULL;
} else if (!i) {
kaddr = page_address(page);
continue;
}
}
kaddr = NULL;
continue;
}
kaddr = NULL;